We have developed unique systems for studying the differentiation of rat lens epithelial cells to fiber cells in tissue culture. We plan to investigate how the cytoskeleton is involved: (1) in the process of differentiation: (a) using primary cells and (b) a cell line, RLE-R which we have obtained by infection of rat lens epithelial cells with Rous Sarcoma virus. (2) In the process of globular degeneration associated with cortical cataract formation, induced in intact rat lenses in organ culture: (a) by drugs affecting the cytoskeleton such as cytochalasin D, colcemide, griseofulvin and vinblastine and (b) by high levels of sugars such as glucose and galactose in the medium, potentiated by calcium. (3) In 2 model systems of globule formation in tissue culture which occurs in old cultures and appears to be a model for aging of lens epithelial cells.